*Excludes Observations that spanned multiple years

  B
b
t
W
w
 
Pre 1970000000
1970000000
1971000000
1972000000
1973000000
1974000000
1975000000
1976000000
1977000000
1978000000
1979000000
1980000000
1981001001
1982000000
1983000000
1984000000
1985000000
1986000000
1987007007
1988015006
1989014005
1990051006
1991250007
1992123006
199301810019
199405870065
199506020062
199606630069
199703320035
199801700017
199901110012
200004410045
200101850023
200201720019
200301830021
200403010031
200501930022
200601550020
200702450029
200806620068
2009004004
201001390022
20110650011
2012070007
201304010041
201402400024
2015006006
2016011002
2017000000
Total36199000712